The choice module in Moodle through 2.6.11, 2.7.x before 2.7.11, 2.8.x before 2.8.9, and 2.9.x before 2.9.3 allows remote authenticated users to bypass intended access restrictions by visiting a URL to add or delete responses in the closed state.Referenceshttps://moodle.org/mod/forum/discuss.php?d=323237http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-51569
